1. Field of the Invention
The present invention relates to a car information indicating apparatus for a plurality of elevator cars at each floor landing in a multi-storey building where more than two elevator cars are providing service to passengers in parallel. More particularly, the present invention relates to an apparatus for operating a plurality of hall indicators, by which a plurality of running information are displayed at the various indicators with the use of only signal relaying means including dual direction communication devices instead of a central processing unit (Hereinafter, referred as CPU). This apparatus results in a more simple configuration of the apparatus.
2. Description of the Prior Art
The communication network for operating a plurality of indicators in an elevator system of the present invention includes a serial communication network which may be considered to be much more advantageous compared to a parallel communication network in that it cuts an operating cost of, and is easy to install and to maintain an elevator system.
Such a serial communication network is normally provided with the plurality of signal relaying means including a CPU for each of floors in a building. When such relaying means including a CPU are used in the system, a plurality of memory devices such as a random access memory (Hereinafter, referred to as RAM) as well as read-only memory (Hereinafter, referred to as ROM) are also needed essentially for each CPU resulting in the elevator system with increased manufacturing costs.
The serial communication network in the elevator system of the present invention is therefore developed not to use many CPUs so as to reduce the manufacturing costs associated with the memory devices described above. In the serial communication network which does not need many CPUs, car controllers should be linked via a plurality of communication lines to a plurality of car position indicators and a car traveling direction indicators installed at each floor landing so as to transmit/receive the respective information representative of a current elevator car position and a traveling direction of a selected elevator car. Such a system needs a plurality of communication lines between them.
For an example, more than 8 communication lines are needed in a building where a single elevator car is running to provide passengers with a service, and more than 16 communication lines are needed accordingly where a two elevator car group is running. Such a large number of communication lines required in the communication network enlarges the size of the signal relaying means and increases manufacturing costs.
The communication network for controlling two elevator cars to operate in parallel fashion will now be described as an example.
FIG. 1 is a schematic block diagram of conventional car information indicating apparatus for a couple of elevator cars. The car information indicating apparatus 10,20 are respectively represented for two elevator cars which are traveling in parallel sharing a single hall call board (in the FIG. 1, every hall call board 16, 17 and 18 is connected to a first elevator car controller 11).
Referring further to the FIG. 1, a conventional car information indicating apparatus 10 for the first elevator car includes a car position detecting means 11D, a car traveling direction detecting means 11E, a car controller 11, a floor controller 12, a plurality of car position indicators 13.about.15 installed at each floor landings, and a plurality of hall call boards 16.about.18. The car position detecting means 11D enables the master processing unit 11A of the car controller 11 to arithmetically calculate the number of total output pulses transmitted from a revolution counter normally installed at a drive shaft of a motor so as to get an arbitrary number representative of the current floor landing at which the elevator car is positioned. The car traveling direction detecting means 11E are normally utilizing either of a clockwise revolution counter for counting the number of clockwise revolutions transmitted from the motor revolution counter or as a counter-clockwise revolution counter for counting the number of counter-clockwise revolution transmitted from the motor revolution counter.
The car controller 11 includes a master processing unit 11A for controlling the first elevator car movement, receiving a plurality of hall call signals, communicating via communication line TL1 with the respective floor controller 12 so as to eventually display the service floor, and communicating via communication line TL4 with a car controller 21 so as to exchange inter-elevator messages. The floor controller 12 incorporates dual port RAM 12A for being capable both of transmitting and of receiving the data, a slave processing unit 12B for exchanging the data with the car controller 11 via the dual port RAM 12A, and two of one-way communication devices 12C, 12D for outputting the data representative of the current car position, movement direction of the respective elevator car and for receiving the hall call signals. The car position indicators 13.about.15 are disposed at each floor, each including a single one-way communication device 13A.about.15A respectively for receiving the data representative of a car position from the floor controller 12 and then transmitting the same data to a digital display matrix 13B.about.15B arranged as a seven-segment display for receiving the data from the one-way communication device 13A.about.15A and then illuminating itself accordingly to display the floor number representative of the current position of the assigned elevator car. The hall call board 16.about.18 is also respectively disposed at each floor landing, each including a one-way communication device 16A.about.18A, a hall call button 16B.about.18B for generating/transmitting the hall call signal to the only communication-purpose repeater 12 via a communication line TL3 and for displaying the elevator movement data received from the floor controller 12, and a car traveling direction indicator 16C-18C in a light emitting diode (not shown) for indicating a traveling direction as either upward direction or downward direction.
Here, the car position detecting means 11D can also be realized as the motor revolution counter or the position detector disclosed in the Japanese Patent No. 86-49671 filed by lkkegima Satomi, et al, and assigned to Mitsubishi Denki Kabushiki Kaisha or the U.S. Pat. No. 4,094,385 respectively. The car position detecting means 11D first of all accumulatively counts the number of output pulses generated at the motor revolution counter installed normally at the motor shaft from the start point until the current time so as to provide to the car controller 11 and the car controller 11 converts incoming count number to a data value representative of how long distance the respective elevator car should move, which is proportional to the count number, compares the distance-related data with a data representative of a distance between neighboring floor landings stored in a memory device, and eventually determines the current position of the elevator car.
The information data representative of the position of the elevator car determined as above can be certified by both a cut-off plate located some distance away from the bottom surface of a floor at which the respective elevator car is stopped to provide passengers with the service, and a position detector installed on the top edge of the elevator car. The position detector installed on the top edge of the elevator car is realized of either a combination of both a light emitting section and a light receiving section or a magnetic flux generating section. The car controller 11 can determine whether or not the elevator car is traveled over distance corresponding to one between neighboring floor landings, as a light signal or magnetic flux is cut off when the elevator car is reached at the respective floor landing resulting in that the cut-off plate becomes to stand between a light emitting section and a light receiving section or the magnetic flux generating means.
The car traveling direction detecting means 11E, as a motor revolution counter outputting pulse signals upon the receipt of either the clockwise motor revolution or the counter-clockwise motor revolution, can be realized with the use both the clockwise revolution counter and the counter-clockwise revolution counter. The car traveling direction detecting means 11E determines as the respective elevator car is traveling upward when there is an incoming clockwise count data, and determines as the respective car is traveling downward when there is an incoming counter-clockwise count data.
As can be seen in FIG. 1, the car information indicating apparatus 20 for second elevator car is constructed as the same as the car information indicating apparatus 10 except the fact that the apparatus 20 does not include hall call boards. The unexplained reference symbols, TL5 and TL6 are communication lines.
The car controller 11 is connected to the floor controller 12 via the communication line TL1, and the floor controller 12 is connected to both of the car position indicators 13.about.15 and to the hall call boards 16.about.18 via the communication lines TL2 and TL3 respectively. Similar to the car information indicating apparatus 10 for the first elevator car, the car information indicating apparatus 20 for the second elevator car is constructed such that its car controller 21 is connected to its floor controller 22 via a communication line TL5, and the repeater 22 is connected to its car position indicators 23, 24 and 25 via a communication line TL6 accordingly.
The car controller 11 for the first elevator car is connected to the car controller 21 for via the communication line TL4 so as to exchange the inter-elevator message, and as a result the first elevator car and the second elevator car may share common hall call board 16.about.18 together at each floor landing. An one-way communication device 22D therefrom is remained not to be connected to anything at all.
FIG. 2 is a block diagram of the car position indicators 13.about.15, 23.about.25 shown in the FIG. 1. Referring now to FIG. 2, each of the car position indicator(13, in the FIG. 2) includes a pulse transformer 13C for receiving bipolar coded car position data via communication line TL2 and amplifying the same data signal to a certain level, an input interface unit 13D for converting the incoming bipolar coded data signal transmitted from the pulse transformer 13C to the binary coded data, a one-way communication device 13A for outputting the same data signal in parallel after recognizing and reading the data, a buffer 13E for temporarily storing the same data received from the one-way communication device, and a digital display matrix 13B arranged as a seven-segment display (used in the embodiment) for decoding the data received from the buffer, and illuminating respective segments being indicative of the arbitrary number of the current car position.
Referring now to the FIG. 3, the operation routine of the car information indicating apparatus 10, 20 will be described assuming that the car information indicating apparatus 10 is a master, and the car information indicating apparatus 20 is a slave accordingly. The car controller 11, 21 independently controls the hall indicating functions of the first and the second elevator car with the use of each slave processing unit 12B, 22B respectively.
Returning to the FIG. 3, if the power is supplied to the system, the system is accordingly activated by in S201. S202 is executed, in which each master processing unit 11A, 21A disposed in car controllers 11, 21 respectively writes the reset data in the dual port RAM 12A, 22A disposed in the floor controller 12, 22 via the communication line TL1,TL5 respectively. Each of slave processing units 12B, 22B thereafter resets the dual port RAMs 12A, 22A by reading the stored data at the dual port RAMs 12A, 22A. After that, each of the master processing units 11A, 21A in the car controllers 11, 21 communicates S203 the inter-elevator messages representative of running information indicating data signal from each other through the communication line TL4 for assigning an optimum elevator car and determines the current position and the traveling direction of the elevator car with the use of the car position detecting means 11D and the car traveling direction detecting means 11E, and then writes S204 the exchanged data at the dual port RAMs 12A, 22A.
After that, each of the slave processing units 12B, 22B sets S205 initial values at the registers of the one-way communication devices 12C, 12D, 22C and 22D after an access to the data stored at the dual port RAMs 12A, 22A.
Then, each of the slave processing units 128, 22B resets S206 the transmission buffer in each of one-way communication devices 12C, 12D, 22C, and 22D with the initial values before the transmission of the data representative of car position, and then checks S207 the status of each one-way communication devices 12C, 12D, 22C, and 22D, and determines S208 whether or not the status of each one-way communication devices 12C, 12D, 22C and 22D is busy.
If the result of the S208 is `not busy`, each of the slave processing units 12B, 22B writes S209 the car position data at the transmission buffer in each one-way communication devices 12C, 22C, and then makes one-way communication devices 12C, 22C transmit S210 the car position data through each of the communication line TL2, TL6 to the respective elevator car position indicators 13.about.15, 23.about.25 at the floor landing which created a hall call request. The respective car position indicators 13.about.15, 23.about.25 thereafter receive the same message through internal communication devices 13A-15A, 23A-25A and sends it to the digital display matrix 13B.about.15A, 23B.about.25B. The digital display matrix 13B.about.15B, 23B.about.25B receives the message from the respective car position indicators 13.about.15, 23.about.25 and displays S211 the arbitrary number of car position accordingly.
The passengers who are waiting for the elevator car at the floor landing can therefore realize the car position and movement direction of the assigned elevator car by looking at the digital display matrix 13B.about.15B, 23B.about.25B of the car position indicators 13-15 and the car traveling direction indicators 16C-18C of the hall call board 16-18.
On the other hand, though it is not shown in the FIG. 3, if one of the hall call buttons 16B, 17B and 18B is pressed at any one of the hall call boards 16.about.18, the hall lamp in the board is turned on immediately and at the same time, transmits the hall call request message out via the respective one of floor controllers 16A.about.18A to the communication line TL3. The slave processing unit 12B in the floor repeater 12 receives the hall call request message via the one-way communication device 12D, writes the message at the dual port RAM 12A. Then, the master processing unit 11A of the car controller 11 receives the same message, reads it, and transmits it to the master processing unit 21A of the car controller 21 for the second elevator. As a result, the two elevators share the common hall call board at each floor so that the efficiency of the elevator system is increased.
However, as explained above, the car information indicating apparatus 20 for a second elevator car is constructed to share both the hall call buttons 16B-18B and the car traveling direction indicators 16C-18C in the hall call board 16.about.18 for the first elevator car through using the one-way communication device 12D of the floor controller 12 so that an one-way communication device 22D of the floor controller 22 may not participate in performing the car information indicating function at all.
In the conventional running information indication apparatus as described above, the slave CPU in each of the floor controllers as well as additional separate networks of communication lines for each elevator car may be needed to perform the hall indicating function resulting in the increased manufacturing cost of the total elevator system. Besides, the monolithic integrated circuit boards used for implementing the floor controller functioning as a signal relaying means is expensive because it is already set up including expensive communication devices for communication and a CPU at the time of purchase so that it may have the limit to reduce the manufacturing cost of conventional car information indicating apparatus to a desired level.